Trouble using external library.

Hello,
I am using CrossWorks for ARM, developing for STM32 Cortex-m3

I am trying to use static library archive that was cross compiled on my pc .
Problem is, that library's header file pulls in some other headers that can't be found in crossworks paths.
for example:
<sys/types.h>
<unistd.h> 

I have checked those files and they are included in my cross compiler installation (from newlib-2.0.0 package)
What should I do now? 
How can I find which version of newlib is used in my CrossWorks? Maybe if I downgrade it to the same version, autotools that configures the library will figure out proper includes.

Thanks for any hints.